It can be really simple.
Stumbled across this …
… and (yes, questionable aesthetics aside) decided to recreate it:

Really does work as advertised:

One-time stuff I had to run:
(ql:quickload 'lass)
(ql:quickload 'spinneret)
(ql:quickload 'hunchentoot)
That’s it. Out of the box. Didn’t start any project, or any framework. Scales up and down, and starts small.
This was less than 10 minutes.